The Passage focuses on Project NOAH, a secret medical facility where scientists are experimenting with a dangerous virus that could lead to the cure for all disease, but also carries the potential to wipe out the human race. When a young girl (Sidney), is chosen to be a test subject, Federal Agent Brad Wolgast (Gosselaar) is the man who is tasked with bringing her to Project NOAH. Ultimately, however, Wolgast becomes her surrogate father, trying to protect her at any cost.